In automobile manufacture, hinge assemblies are used to pivotally secure closure panels such as tail gates, trunk lids, bonnets and/or hoods to the vehicle frame, or any other type of closure. Conventional car hinges consist of a pair of steel hinge arms which are movably connected to each other by one or more pivots, and which are bolted respectively to one of the closure panel and the car frame. To maintain the car hood in an open position, as for example to permit servicing of the engine, it is known to provide either supplementary gas-charged struts or a prop rod in conjunction with the hood hinges.
The use of hinge mechanisms in conjunction with gas-charged struts advantageously enables the hood to be opened or closed by only one hand of the user. As the hood is opened, gas pressure within the strut acts as a counterbalance to the weight of the hood, and helps to open and hold open the hood/closure panel by supporting the weight of the hood through the force generated by gas pressures within the struts. To close the hood, the user merely applies an added minimum downward pressure on the hood which is sufficient to overcome the resistive force of the struts. Gas struts suffer disadvantages, however, in that over time as a result of wear and seal failures, the struts tend to lose their effectiveness and may require replacement. In addition, as a practical matter, the increased manufacturing costs of gas struts has resulted in their limited use to date. In particular, gas struts are used almost solely with more expensive luxury automobiles, sport utility vehicles and/or vehicles designed with ergonomic difficulties for the end user to open or close the closure panel.
Conventional hood hinge assemblies used with less expensive vehicles are most often provided in conjunction with an elongated prop rod which is hingely mounted along the front of the vehicle under the hood. These hinge systems suffer the disadvantage in that they require two handed operation. In particular, in use, it is necessary to hold open the hood with one hand, and thereafter release, raise and position the prop rod with the other hand, typically orienting the end of the prop rod within a slot or opening formed in a forward underside portion of the hood. When closing the hood, two hands must again be employed, with one hand used to partially raise the hood a certain amount to allow the upper end of the prop rod to be disengaged from the hood slot, and the other to simultaneously lower and reposition the prop rod in a storage operation.
In an effort to attempt to overcome some of the disadvantages of prior art devices, U.S. Pat. No. 6,892,843 B2 to Schillaci et al describes a prop assembly for use in securing a vehicle hood in an open orientation, without the use of a conventional prop rod. In Schillaci, the hinge itself is provided with a rigid prop member which is pivotally connected at an upper end to the hood hinge arm. The lower end of the prop rod is slidably received within a guide slot which extends in an inclined orientation along the car body away from the hinge pivot, and which includes at a proximal most downwardly extending detent. The lower end of the prop rod drops into the detent as the hood is fully opened, to thereby brace the hinge arm in the open orientation.
Schillaci suffers a disadvantage in that to release the hinge and close the hood, it is necessary for an individual to stand to the side of the car adjacent to the hinge, and manually raise both the hood and the end of the prop rod from the detent by means of a release lever. Schillaci therefore continues to require a two-handed operation of the hinge assembly in closing operation. In addition, because the prop rod is released from its position with the user standing beside the vehicle, Schillaci suffers further disadvantages in that it is difficult for shorter and/or physically weaker users to raise the hood when standing to the vehicle side, as in such a position almost the entire weight of the hood is forward from the user. In addition, with Schillaci once the prop rod is released, it may be necessary for the user to reposition him or herself in front of the car to thereafter secure the hood closed in a fully latched configuration.